A common rail fuel injection system configured to avoid a fault in determining common rail fuel pressure

摘要

A common rail fuel injection system, comprising: a common rail (12) for storing fuel therein at a predetermined pressure to be injected into an engine (10), a fuel pressure sensor (16) including a sensor element (16a) for outputting a voltage signal as a function of a pressure of the fuel within the common rail, an electronic control unit (20) comprising a power supply circuit (22) adapted to supply a constant power supply voltage (Vc) to the fuel pressure sensor by means of a wire harness ( 30), wherein the constant power supply voltage is used in the fuel pressure sensor as a drive voltage applied to the sensor element, and wherein the electronic control unit for controlling the pressure of the fuel in the common rail is based on the voltage signal supplied from the fuel pressure sensor the electronic control unit via a first signal line (33) is output to a voltage sensing circuit (18, 25, 26) for sensing the driving voltage applied to the sensor element of the fuel pressure sensor via a second signal line (34) disposed in the wire harness (30) such that it is separate from the first signal line (33) and a voltage error monitor (21) used to monitor whether the drive voltage as sampled by the voltage sensing circuit (18, 25, 26) is faulty or not.